We're testing out a new template/design for one of our email campaigns and we're running an A/B test with the original content vs the new design. The subject line, preheader and sender name are all the same; however, the original is having is showing noticeabley better open rates? The new template design is a slightly larger email, which is the only thought I have as to what's causing a 7% point difference in open rates.
I would love any insight or thoughts anyone else can share.